This study investigates how Finnish-speaking researchers at the University of Oulu cooperate with language editors in writing scientific articles in English. There is not enough awareness of the different aspects and benefits of this kind of cooperation, despite the fact that for researchers writing for scientific journals is an important part of their work. This thesis is a case study. There was no empirical research about the cooperation between researchers and language editors during the writing process of scientific articles before this study. In order to find out what the Finnish-speaking researchers at the University of Oulu think about their writing process and proofreading, they were asked to fill in an online questionnaire. The purpose of the questionnaire was to study how the researchers would like to cooperate with language editors at the beginning, middle and end of the writing process. After this, six researchers were asked for interviews. The interviewees were asked how they cooperate with language editors and what kind of feedback they find most useful for their writing. The answers were broken into themes for thematic analysis. More than a half of the informants reported in the questionnaire that they would benefit from more cooperation with a language editor. The interviewees estimated that cooperation would help to find ways to structure and present the content of their articles. This study revealed that there is a need to develop cooperation between the researchers and language editors at the University of Oulu. The cooperation should be based on the researchers’ field of research, experience, aims and language skills.